Speed-regulator system



WITNE SES 1 32/ Again, 1928. 1,665,901

J. H. ASHBAUGH S PEED REGULATOR SYSTEM Filed Sept. 26, 1925 I in N lNVEN'IOR Jo/m HAS/Maggi).

Patented Apr. .10, 1928.

UNITED STATES 1,665,901 PATENT OFFICE.

JOHN H. ASHBAUGH, O1 PITTSBURGH, PENNSYLVANIA, ASSIGNOB TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A COBIORATION OF PENNSYLVANIA.

SPEED-REGULATOR SYSTEM.

' Application filed September 26, 1985. Serial No. 58,888.

My invention relates to regulator systems and more particularly to systems for regulating the speed of electric motors.

7 One object of my invention is to so regulate the speed of the controlled motor that it will follow the speed of a reference motor or clock device.

A further object of my invention is to provide a regulator of the above-indicated character in which the corrective tendency is cumulative, accurate, and quick acting.

My invention contemplates the use of a regulator of the vibratory type that intermittently short-circuits a resistor in series relation with a field winding of the controlled motor. The regulator comprises a pair ofcooperating contact members, one of which is actuated by a air of regulator mag nets that are energized from a pilot nerator driven in accordance with the speed of the controlled motor. The other regulator contact member is actuated by a differential device that is responsive to the speed. difierg ence between the controlled motor and a speed-reference means, such as a clock or a motor. p

' My invention will be better understood By reference to the accompanying drawing, wherein the single figure is a diagrammatic view of the apparatus embodied .in a preferred form of the invention.

Referring to the drawing, a controlled motor 1 having an armature winding 2 and a field winding 3 is illustrated as connected to 'a suitable source of energy, such as supply conductors 4, 5. A variable resistor 6 1s provided in series with the field winding 3,

and a pilot generator 7 having an armature winding 8 and a field winding 9 is connected to be driven in accordance with the speed of -adjusting rheostat 11 the motor 1. A

' is provided in series with the field, winding 9 of the pilot generator. -Thepilot generator 7 is further providedwith a pair of slip rings 12, 13 so that alternating current may be taken from the generatoryand asinglephase synchronous motor 14 is connected to be operated in accordance with the speed of the pilot generator 7 and, eonsequently,- of the motor 1.

The synchronous motor 14 drives one sideof a mechanical difierentialdevice 15, and av I single-phase synchronous motor16is. pro-' vided for the other side of the difdevica. 16

.the regulator 25, and the normall speed thereof.

is; actuated in accordance with the speed of a reference means, such as a clock, or a enerator 17- that is driven by a three-p ase synchronous'motor 18. The differential deand 21, which are respective] the motors 14 and 16, and a middle or planetary gear wheel 22, which is responsive to the differential speeds of the end gear wheels, andactuates a contact -member 23 that cooperates with a contact member 24 of a regulator-25 so as to control relays 26 and 27. a

The regulator 25'is of a well-known type and comprises a control magnet 28 and an anti-hunting magnet 29 that are respectively provided with coil windings 31' and 32, which are connected in arallel circuit relation to each other, an ductors 33 and 34 to brushes 35 and 36 of the pilotagenerator 7. Resistors 37 and 38 are provi The regulator magnets are also connected through a resistor 39 to the armature of the controlled motor 1.

Theoperation of the regulator magnets by means of con- 7 ed in'circuit with the windin 31 and 32 of the regulator magnets 28 am l 29, respectively.

28 and 29 actuates the contact member24 to I engage and disengage the contact member 23, so as toconnect the operating windings of the relays 26 and 27 with supply con- 'ductors 41 and 42. The normally open relay 26 operates to short-circuit a portion of the resistor 38 toprevent hunting action of v closed relay 27 is operative to intermittent y shortcircuit the resistor 6 in the field circuit of the" controlled motor so as to govern the N The regulator 25 operates to maintain a constant voltage upon the pilot generator 7 by varying the excitation of the motor field winding 3 to govern the motor The setting of the speed-adjusting eostat 11 determines the particular speed of the pilot generator 7 that is necessary to produce the normal voltage for which the regulator 25 is ad'usted; or that voltage which corre- -spon to; the speed of the controlled motor 1.

shouldthespeedof themotorlcorrespond to that-ofthe reference motor 18, so

that the synchronousmotors 14 and 16-02 crate at the samespeed and hold the posi- "tion of the constant, the

control of the motor 1 would depend entirely upon the voltage impressed upon the regulator 25, and the operation of the regulator would be independent of the contact member 23. That is to say, the voltage of the pilot generator 7 would determine the operationv of the regulator, 25 in the same manner as'though a fixed contact member 23 were used.

Should the speed of the motor 1 vary from that of the reference motor 18, however, the mechanical diiferential device 15 would cause the contact member 23 to be moved toward or away from the contact member 24, thereby necessitating a lesser or a greater movement of the contact member 24 to again close the circuit of the relays 26 Changing the position of the contact member 23, therefore, changes the setting of the re ulator or changes the voltage of the pi ot generator that is necessary to cause the regulator to-maintain a constant p 1. a This change in the setting of the regulator is very rapid and is cumulative in effect, so that the motor 1 will closely follow chan es 1n speed of the ref erence motor 18 an will quickly adjust itspeed ofthe motor self for changes in the excitation of field winding 3 as necessitated by changes in load.

Many modifications in v the apparatus and in the arrangement of arts may be made within the spirit of my invention, and I do not wish to be limited other than by the scope of the appended claims,

I claim as my invention 1. In combination, a s cod-reference means, a dynamo-electric mac ine having a field winding, means for regulating the excitation of said field winding comprising a air of contact members, means for actuatmg one of said contact members in accordonce with thespeed of said dynamo-electric machine, and means for actuating the other of said contact-members in accordancewith the differential speeds of said speed-reference means and said dynamo-electric.machine.

2. In combination,

a -reference means, a dynamo-electric machine havinga erator for actuating the second of said coni'naccordancc with the difierential speeds of said speed-reference means and said dynamoelectric machine.

3. In combination, a speed-reference means, a dynamo-electric machine having a field winding, means for regulating the excitation of said field winding comprising a pair of contact members, a pair of electromagnets for actuating one of said contact members, means for energizing one of'said magnets in accordance with the speed of said dynamo-electric machine, and means for actuating theother of said contact members in accordance with variations in the speed of said dynamo-electric machine from'- its desired value.

4. In combination, a speed-reference means, a motor having a field winding, means for regulating the-excitation of said field winding comprising a pair of-oontact members, a diflerential dev1ce\responsive to the speeds of said reference' means and said motor for" actuating one of said contact members, and means for actuating the otherofsaid contact members in accordance with the speed of said motor.

5. In combination a speed reference means, a motor having a field .winding,

a pair of electro-' means for regulating the excitation of said field winding comprising a pair of contact members, a differential device responsive to the relative speeds of said reference means and said -motor for actuating one of said contact members, a. pilot generator actuated by said motor, and means ener d in accordance with the speed of sai pilot gentact members. Y

In testimony whereof, I have hereunto subscribed my name this 15th day of September, 1925.

- JOHN H. ASHBAUGIL 

